fix: address review findings in PR #62

- Restore nil-safety guards on activeItemSet["Weapon 1/2"] and the
  weapon1Sel==0 check before indexing items[], preventing crashes on
  any import where the weapon slots are empty (MaceStrike path)
- Restore craftedMods parsing in ImportItem so API-imported items with
  crafted mods are not silently dropped; restore "crafted" lineFlag in
  Item.lua and the {crafted} prefix in BuildRaw for round-trip fidelity
- Restore socket-group reimport state preservation (snapshot before
  wipe, apply after re-import) so gem enabled/count/skill-part settings
  survive a re-import
- Restore ArmourAppliesToElementalDamageTaken branch in
  buildDefenceEstimations so elemental armour application is counted
- Restore deflection chance formula to clamp(100-NotDeflect, 0, Cap)
  which correctly caps the deflect chance; the PR had inverted the
  clamp so it could produce 100% deflect on extreme evasion values
- Add regression test for nil-safe Mace Strike import with empty slots

https://claude.ai/code/session_01SECwiNXHCfV3g7WLQ7UNjD

Author: claude

spec/System/TestImportTab_spec.lua

@@ -54,6 +54,27 @@ describe("ImportTab", function()
 		assert.are.equals(2, #item.runeModLines)
 	end)
 
+	it("ImportItem returns nil (not crash) for Mace Strike with empty weapon slots", function()
+		local importTab = build.importTab
+		-- Simulate a character skill with typeLine "Mace Strike" but no weapon equipped
+		-- activeItemSet slots exist but have selItemId == 0 (nothing equipped)
+		local mockItemData = {
+			typeLine = "Mace Strike",
+			name = "",
+			frameType = 4,
+			inventoryId = "Flask",
+			x = 3,
+			id = "flask1",
+			ilvl = 1,
+			mirrored = false,
+			corrupted = false,
+		}
+		-- Should not crash even when Weapon 1/2 slots are empty (selItemId == 0)
+		assert.has_no.errors(function()
+			importTab:ImportItem(mockItemData, "Flask 3")
+		end)
+	end)
+
 	it("builds character lists for private Ruthless league names without a Ruthless tree", function()
 		local importTab = build.importTab
 		importTab.lastCharList = {